In order to discriminate and identify phytoplankton of different genuses, the second scaling function of Daubechies-3 was selected to extract the characteristics of 10 phytoplankton species. The results of Bayes discriminant analysis show that these characteristic spectra show a discriminating rate of 96.75% at genus level. Standard spectra were obtained from these characteristic spectra. The results of the nonnegative least square show that they can identify qualitatively some single species added with dif...